The Seeking and Scanning Behavior Project under CECCR I (SSB I), established the frequent use of nonclinician information sources among a large representative sample of patients with colon, breast and prostate cancer, as they made post-diagnosis decisions related to treatments and quality of life. There is evidence from that study that use of these sources (e.g., personal sources, such as friends and families;impersonal sources, such as internet) is related to several important behaviors. However, while the specific aims of SSB I focused on the role of non-clinician information sources, the study also makes clear that the information exchange between clinicians and patients was central for these patients. The proposed project builds on this finding and focuses on the role of medical information sources and patient-clinician communication in an oncology setting. There is a substantial literature about patient-clinician communication: describing it, making normative claims about what patterns of communication are most productive, testing short term effects of experimental interventions meant to improve such communication, and, more rarely, examining longer term health effects of variation in such communication [1].There are, to our knowledge, no studies that test the longer term effects of natural variation in physician-patient communication on important health outcomes among a representative sample of cancer patients. The proposed study will be the first to undertake this task. Our prior CECCR study randomly drew a sample of cancer patients from the Pennsylvania Cancer Registry: 2013 breast, prostate and colon cancer patients provided baseline data within 12-20 months of their initial cancer diagnosis;1296 provided follow-up data one year later. The baseline and follow-up questionnaires document the complex information exchange between patients and their physicians: the great majority of patients (75%) reported actively seeking treatment and other information from their treating physicians. However patients varied in the extent and content of other interactions with their physicians: whether and from what sources they brought information to their physicians;how often their physicians directed them to other interpersonal and mediated sources;whether they sought quality-of-life information from their physicians; whether they received recommendations from their physicians about lifestyle behavioral changes and other follow-up behaviors;whether they could get information they wanted from their physicians;whether they sometimes avoided talking with their physicians about their questions;and whether their physicians shared decision-making with them to the extent that the patient desired. Patients also varied sharply in their use of non-clinician information sources, including personal sources and mediated sources. The proposed longitudinal study will focus on variations in patient-clinician information exchange around cancer diagnosis and treatment (a component of patient-clinician communication). On the one hand we propose studying whether patient-clinician information exchange is associated with and predictive of important health management decisions, behaviors and outcomes, including treatment choices, adherence with physician recommendations for tests and medications, lifestyle behavior changes, maintenance visits to physicians, and treatment-associated morbidity (Study One) and, on the other hand, whether physician-patient information exchange is a function of different patterns of physician visits (as documented in Medicare administrative claims data) and other socio-demographic and illness characteristic determinants (Study Two). The proposed Study One also will test whether the level of patient-clinician information exchange influences the effect of exposure to non-clinician information on these outcomes. Both studies will use three data sources: (1) we will fully exploit the available data from the first two rounds of the cancer patient survey from SSB I, a unique resource, to examine new research questions;(2) we will match the data from the surveys to Medicare administrative claims for those patients [unreadable] 65 years, which will allow us to move from dependence on patient self-report alone to a more objective form of evidence about patient-clinician visit patterns and about health outcomes;and (3), we will obtain a third round of questionnaire data from cancer patients who provided data in the first two rounds - of the 1296 patients who provided data at the follow-up round, 91% have agreed to provide data for a follow-up questionnaire. The proposed study will (a) provide previously unavailable evidence to assess the relationship between one form of patient-clinician communication and hypothesized effects of such communication and (b) if there is such evidence, allow development of recommendations to encourage and facilitate the types of patient-clinician communication associated with improved health outcomes.